Mineral Point tribune. (Mineral Point, Wis.) 1869-1938, 1887-02-03
PRECIOUS METALS.

How Gold and Silver Are Refined at the Assay
Office.
In the very heart of Wall street, says
The New York Post, are the United States
sub-treasury and the assay Office. Here
is the true heart of the financial world; if
it is irregular in it's beating, notice how
quickly the speculative pulse is affected.
The sub treasury deals with money after
it is coined but the assay Office takes the
virgin gold and silver, or these metals
when they are debassd, and determines
their value, using the government stand
and of coinage as basis.
The office is intended to accommodate
the bullion interests OF New York, and il
is used by brokers, bankers, merchants,
and jewellers. Any one having gold OF
silver which, when essayed, will amount to
800 or over may deposit it. He will re-
ceive its value in cash or in fine gold, or,
if it is silver, in fine silver bars. The
gold and silver bars have their weight
stamped upon them, and the former bears,
under the government seal, the value in
gold coin as well. The use of these bars
has saved the government heavy
expense, "a they have been largely en-
ployed in the arts and manufactures, thus
preventing the melting down of gold To
determine just how an exchange shall be
made chip is taken from the metal
brought to be assayed, and it is melted by
itself and poured into mould These
small samples are assayed, and by Calcu-
lation the proportion of pure metal is
dicated. OF course, deduction must be
made for the cost of parting, refining,
etc, but the net result is paid to the de-
! positor.
1
To obtain the best results in the separa-
ting, department are so combind that the
gold granulations shall have over two
parts of silver to one of gold, care being
taken that any capper that may be present
shall not exceed per cent. of the mixture.
About 25,000 ounces can be treated in
four kettles. The acid is added to the
examinations in successive portions from
a reservoir on a floor above, into which 1t
is forced by air pressure from a receiving
cylinder in tho basement. 1t is boiled
about five hours, then allowed to cool, ard
afterward siphoned into silver reducing
! tanks, four in number. The removal of
the silver in the acid solution leaves the
gold IN the dissolyiug kettle to this fresh
acid is added, and it is removed to an
other kettle, acid being again added
twice The resulting weak solutions of
silver are siphoned off, and after the third
repetition of this process gold results,
which when melted, fiuxed, and cast into
bars, is 9971-1 900 to 99S 900 fine.
| The solution of silver which is obtained
| by the Ave process is after a settling
process bolted by the application of
steam about five hours in lead watts. In
these copper plates are plunged, a por
ton of the copper gradually replacing
/ the silver in the solution. The copper
| solution is then siphoned into concen-
trating tanks and the silver after being
soraped from the copper plates, is placed
in filter, where it is washed, and, when
melted, it is found to be from 999 to $685.
thousandths fine.
Tho men, who are busily engaged eight
hours day in pouring molten gold from
crucibles into molds, are as careless in
their actions as if they were handling
iron. If 1t were possible for any class
of men to grow tired of the CLINT of gold,
these men must be the fortunate individ
uals. Someone undoubtedly keeps a
csse watch on them, but il is not appar-
| ent, and they do not seem to be retricted
| in their freedom because the work in the
precious metal. When they haye finished
work they change their clothing and go
home. There has been but one arrest
among them for years. A few dollars
worth of gold was found in the pocket OF
a workman, out the grand jury did not
/ find against him, the inference being that
some enemy had placed it there.